Means for treating substances



Dec. 17, 1935. O E 2,024,854

MEANS FOR TREATING SUBSTANCES Filed June 4, 1954 2 Sheets-Sheet 1 IN VENTUR- //ENB G50 12 GE A 7701a NE {is Patented Dec. 17, 1935 UNITED STATES PATENT OFFICE.

IMEANS FOR TREATING SUBSTANCES Cirey, Paris, France Application June 4, 1934, Serial No. 728,825 In France June 8, 1933 1 Claim.

This invention relates to a method and means for treating substances which are readily attacked by air when in a hot state and relates more particularly to means for melting and casting magnesium, its alloys and compounds, aluminum and other metals and materials, which are readily oxidizable when they are heated or when they are in a molten state.

It is known in prior art to fuse a metal in a furnace and to pour the molten metal into a mold which is temporarily connected with this furnace. It was found, however, that in many instances the metal which solidifies in the mold is defective, due to the fact that the gaseous atmosphere in the mold is different from that in thefurnace, and also because the molten metal is exposed to outside air while it is poured from the furnace into the mold.

An object of this invention is to improve the processes of melting and casting magnesium and other substances by regulating in substantially the same manner the nature and the pressure of the gaseous medium passing over the molten substance both in the furnace and in the .mold and by preventing the molten substance from coming in contact with the outside air while it is being poured out of the furnace and into the mold.

The above and other objects of this invention may be realized through the provision of two air tight containers which serve as a furnace for melting the magnesium and a mold for the molten substance, and through the provision of means interconnecting the interiors of the two containers in parallel and in such manner that gaseous currents of substantially the same nature and the same pressure may pass through the two containers, separate means being provided to pour the molten substance from one container into the other container without exposing itto outside air.

It is advisable to use a rotatable electrical furnace for melting the magnesium since in furnaces of this type the molten substance is not subjected to attack by gases resulting from the combustion of the heating means of a furnace of the usual type. I

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing a preferred embodiment of the inventive idea.

In the drawings:

Figure 1 shows a furnace in side elevation and partly in section.

Figure 2 is a section along the line 2--2 of Figure 1, looking in the direction of the arrows.

Figure 3 shows on a larger scale and in section the mold attached to the furnace and the device for connecting the interior of the furnace with 5 the mold.

In the drawings, a furnace 5 is provided with a metallic cylindrical casing 6 surrounding a layer of heat insulating, material I as well as a lining 8 made of a refractory material. The 10 external cylindrical casing 6 is closed at its two ends by two covers 9 and H] which are rigidly connected with the casing 6 by angle irons H.

A heating rod or resistance 12 is situated within the furnace 5 and is supported at its two 15 ends by insulators l3 and I3a. Terminals l4 and Ma are connected with the ends of the heating rod l2 and may be connected with a source of electrical energy which is not shown in the drawings. 20

A casing 4 supports the insulator l3 and is carried by a support I5. A similar casing 4a supports the insulator Ba and is carried by the support l5a.

The furnace 5 is supported by two pairs of 25 rollers l6 and H. The rollers ll (Fig. 2) are carried by supports Ila and are in engagement with an annular guide I8 which is rigidly connected with the casing 6. The rollers I6, only one of which is shown in the drawings, are car- 30 ried by the support |6a and engage an annular guide I 9 which is rigidly connected with the casing 6.

The furnace 5 is rotated-by a toothed wheel 20 which-meshes with a toothed annular crown 5 2|, rigidly attached to the casing 6. The toothed wheel 20 is driven by a motor 22 through the medium of several gear wheels situated within the gear box 23.

While the furnace 5 is rotated, the electrode I2 40 and the casings 4 and 4a remain stationary. A suilicient amount of packing material 24 is pro vided between the cover 9 and the-casing 4 to prevent the outside air from penetrating into the interior of the furnace 5.

Similar packing material 25 is provided between the cover Ill and the casing 4a. Airtight packing material 26 is also provided between t e casings 4 and 4a and the insulators l3 and l3a. 50

A mold 30, shown on a larger scale in Figure 3, comprises a lower portion 33, which is detachably connected with the upper casing 34 by flanges 35 and bolts 36. The mold casing 33 is connected with the casing 34 in such manner 55 'that atmospheric air cannot penetrate into the interior of the mold. The upper casing 34 is connected with the casing 6 by rivets 3| passing through a flange portion 32 of the casing 34. Any number of removable mold casings 33 may be attached, one after the other, to the casing 34.

The interior 31 of the furnace 5 is connected with the interior 38 of the mold 30, by a passage 39. This connection may be interrupted by a conical stopper or plug 40, fitting into a correspondingly shaped portion of the passage 39.

The plug 40 is attached to one end of a threaded rod 4|. The opposite end of the rod 4| is rigidly connected'with a piston 42 which is slidable within a hollow tubular casing 43. The opposite end of the tube 43 projects through a wall of the casing 34 and is provided with a handwheel 44. 'A stufling box nut 45 surrounds the tube 43 and. is screwed into an opening formed in a flange 46 which constitutes a part of the casing 34. Suitable packing material 41 is placed around the tube 43 between the stufling box nut 45 and the flange 46 to prevent atmospheric air from penetrating into the interior of the casing 34. The end 48 of the tube 43 is provided with inner screw threads meshing with the screw threads of the rod 4| and is carried by a sleeve 49 which is attached by a bolt 50 to a wall of the upper mold casing 34.

The casing 40. is provided with a pipe 5| which carries a valve 5|a and through which a gaseous current under any suitable pressure may be introduced into the interior of the furnace 5. A similar pipe 52 provided with a valve 52a is connected to the casing 4 and serves as an outlet for the gaseous current after it has passed through the furnace.

A pipe 60 is attached to the cover l and communicates with the interior of the furnace at the point where the gas current enters into the furnace. The pipe $0 is connected with a pipe 6| the opposite end of which is connected with the casing 34. A valve 62 is carried by the pipe 5|.

The opposite end of the casing 34 is connected with one end of the pipe 63 which is provided with a valve 64. The pipe 63 is connected with another pipe 65 which is attached to the cover 9 and leads to the interior of the furnace 5 at the point where the gas current leaves the furnace.

Due to this arrangement the same gas current which passes through the furnace 5 also passes through the mold 30 with the result that the molten magnesium both in the furnace 5 and in the mold 30, is subjected to the same treatment.

The device operates as follows:

Magnesium or other substance is placed into the interior of the furnace 5; then the terminals I4 and Ma are connected with a source of electrical energy, so that an electrical current passes through the electrode |2. The furnace 5, is rotated by means of the motor 22 driving the gear wheel 20 which meshes with the toothed crown 2|.

While the furnace 5 is rotated, the lower mold casing 33 may remain attached to the upper casing 34 and may be rotated along with the furnace 5, as shown in Figure 1 of the drawings.

It is possible, however, to remove the mold casing 33 before the motor 22 is started and to attach the casing 33 to the casing 34 only after the rotation of the furnace 5 has been terminated (Fig. 2).

In both instances, the passage 39 should be tightly closed by the plug 4|) while the furnace 5 is being rotated to prevent the molten sub- 5 stance from leaving the furnace.

The plug 40 is inserted into the passage 39 by the rotation of the hand wheel 44 which is rigidly connected with the tube 43. The tube 43 is prevented from shifting in the direction of its 10 axis through the provision of a bolt 1| carried by the sleeve 49 and projeeting into a groove 12 formed in the end portion 48 of the tube 43. The rotation of the end portion 48 provided with inner screw threads meshing with the screw threads of the rod 4| is transformed into a movement of the rod 4| in the direction of its longitudinal axis, said rod being prevented from rotating through the provision of a pin 13 projecting into a longitudinal groove 14 formed in the rod. Since the plug 40 is rigidly connected with the rod 4| it will move along with it.

The plug 40 is moved to the left (looking in the direction of Figure 3) to open the passage 33 after the completion of the melting process, when the rotation of the furnace 5 has been interrupted and when the mold casing 33 has been securely attached to the upper casing 34.

The pipe 5| (Fig. 1) is connected with-any suitable means not shown in the drawings, for supplying a gaseous nonoxidizing current of a predetermined nature and having a predetermined pressure to the interior of the furnace 5. The gaseous current flows through the pipe 5| into the interior of the casing 4a. The main portion of the current will flow through the furnace 5 in a direction toward the casing 4. A certain part of the current will pass through the pipes 60 and 6| into the interior of the mold 30, leaving the mold through the pipes 63 and 65. 4-0 The entire gaseous current leaves the furnace 5 through the casing 4 and the pipe 52.

Thus the molten substance 10, when flowing by gravity through the passage 39 into the interior 38 of the mold 30, is not exposed to outside air.

When the mold is filled with the molten substance, the plug 40 is again inserted into the passage 39, and after solidification of the substance in the mold, the mold casing 33 is separated from the casing 34 and the finished casting is removed from the mold casing 33.

What is claimed is: Means for treating substances which ar readily attacked by air when in a hot state, comprising in combination a rotatable air-tight fur nace, a heating rod situated within said furnace and adapted to be heated by an electrical current, an upper casing firmly connected with said furnace and rotatable therewith, said upper casing being situated adjacent to a passage formed in said furnace for the molten substance, means carried by said upper casing for closing and opening said passage, a removable mold casing adapted to be connected in an air-tight manner with said upper casing, said passage interconnecting the interiors of said furnace and said mold casing, and means connected with said furnace and said upper casing for passing gaseous currents of substantially the same nature and pressure through said furnace and said mold casing.

HENRI GEORGE. 

